Lesson 75: Dolphins

Dolphins are highly intelligent marine mammals. They belong to the family of toothed whales that includes orcas and pilot whales. They are found worldwide in shallow seas of the continental shelves. They are carnivores and mostly eat fish and squid.

Dolphins are generally grey in colour. Their backs are darker than the rest of their bodies. Dolphins have a fin at the top and flippers on the side. They breathe air through a hole on top of their head. A baby dolphin is called a calf.

Dolphins are well known for their agility and playful behaviour. Many species will leap out of the water, spy-hop (rise vertically out of the water to view their surroundings) and follow ships. Scientists believe that dolphins conserve energy by swimming alongside ships, a practice known as bow-riding.

Dolphins live in groups of five to several hundred. Most live long lives. The bottlenose dolphin can live for over 40 years and the orca can live to be 70 or 80!

A) Vocabulary

Marine – belonging to the seas and oceans
Mammals – A warm-blooded animal that has hair or fur, females secrete milk for the nourishment of the young, and give birth to live young.
Shallow – not deep
Continental shelf – the edge of a continent that lies under the ocean
Carnivores – animals that eat other animals
Fin – A flattened part on various fish used for propelling, steering, and balancing
Flippers – a flat limb without fingers used for swimming
Agility – the ability to move quickly and easily
Conserve – save or protect

B) Discussion Points

  1. Identify five mammals.
  2. Choose one mammal and describe it in 4-5 complete sentences.
  3. Find 5 fun facts about dolphins.
  4. How is a continental shelf formed?
  5. Have you been to the zoo?
  6. What animal did you enjoy watching and why?